Clesrovimab: a new monoclonal antibody in the dm+d
The NHS Business Services Authority has added clesrovimab to the dm+d dictionary (version 6.1.0). Clesrovimab is a monoclonal antibody that targets the respiratory syncytial virus (RSV) F protein, used for passive immunisation in high-risk infants during RSV season.
What is clesrovimab used for?
Clesrovimab provides season-long protection against RSV disease in vulnerable infants. It is administered as a single intramuscular injection of 50 mg/kg, typically during autumn and winter when RSV transmission is highest. The drug is reserved for high-risk groups, including infants with congenital heart disease, chronic lung disease, or significant prematurity.
Event-medicine relevance
Clesrovimab is not typically administered at events. It is a preventive agent given in primary care or hospital settings before RSV season begins. Event responders are unlikely to administer this drug. However, if an infant with a recent clesrovimab injection presents with signs of anaphylaxis or severe hypersensitivity reaction, treat as per your anaphylaxis protocol and escalate urgently to hospital.
Key cautions and interactions
- Bleeding risk: Avoid IM injection in infants with thrombocytopenia or active bleeding disorders.
- Acute illness: Consider deferral if the infant has fever or acute illness at the time of scheduled injection.
- Live vaccines: Defer live attenuated vaccines for at least 3 months after clesrovimab administration.
- Inactivated vaccines: May be given concurrently at different injection sites.
- Immunocompromised infants: Efficacy may be reduced; clinical benefit should be assessed on a case-by-case basis.
Monitoring and side effects
After injection, observe the infant for 15–30 minutes for signs of hypersensitivity. Monitor vital signs (temperature, respiratory rate, oxygen saturation). Common side effects include injection site reactions, fever, and irritability. Serious but rare reactions include anaphylaxis and severe hypersensitivity.
Further information
Always verify current dosing and indications against the BNF and the product SmPC before administration. For MHRA product information, visit medicines.org.uk.
This entry is informational only and is not a substitute for professional clinical judgement. Clesrovimab is a specialist paediatric immunisation agent; event responders should escalate any adverse reactions and confirm administration history with parents or carers.